In immunohistochemistry, how the sample is prepared is important for preserving the antigens in the sample. Of all the steps, sample fixation and embedding are the most important, and the protocol must ensure the sample maintains its structural integrity and antigenicity.
Why Coat Slides?
After preparing tissue samples for immunolabeling, incubations are performed according to protocols that maximize the desired signal and minimize background noise. Some of these protocols may remove the tissue section from the glass slide. Typical adhesives used for tissue section such as poly-L-Lysine, Elmer's glue, and chrome alum cannot be used with immunogold labeling because there is an increased background due to the attraction of the gold particles to the adhesive on the slide.
In addition, the surface of the glass slides is uneven and the silicon tetrahedral structure activates it. This provides reactive sites for the adsorption of proteins or chemical reactions with reagents. Hence, the coating material should have low reactivity toward reagents.
BIOBOND™ provides a strong adhesion between the glass and tissue section for further incubations. It forms a coating layer on the glass surface that reduces the interaction of the charged glass surface with the reagents. This is important for reproducible results as the properties of glass slides from different sources may differ. The adhesive is particularly useful in extreme incubating conditions as those used in situ hybridization.
Simple Coating Procedure
BIOBOND™ has a simple coating procedure. Using the following protocol, about 100 slides can be coated. Disposable rubber gloves should be worn when handling BIOBOND™
- Metal or plastic racks are loaded with slides. Twenty slides at a time is a convenient number.
- The racks are placed in a 2% solution of Decon detergent and left for 1 hour.
- Use clean tap water (or distilled water if the tap water is not clean) to remove Decon completely.
- Slides should be dried either in air or at 40 ºC and covered to protect from dust.
- A 2% solution of BIOBOND™ is prepared in acetone (general purpose reagent), 2 ml in 100 ml.
- The rack with the slides is immersed in BIOBOND™ solution for 4 minutes.
- Then, the racks are rinsed in clean tap water or distilled water, and dried in air.
- After the slides are completely dry, they are stored in a dust-free environment (usually the original slide box) for future use.
The slides are ready for mounting sections and can be stored indefinitely. A 100 ml solution of BIOBOND™ can coat at least 100 slides using this method.
BIOBOND™ is suitable for various types of tissue samples such as paraffin wax or resin sections, cell smears, cytospins, or cryostat sections. BIOBOND™ is available in 20 ml packages, enough to coat at least 1000 slides.
This information has been sourced, reviewed and adapted from materials provided by Ted Pella, Inc.
For more information on this source, please visit Ted Pella, Inc.